Pulsed-Laser-Driven TEM for Studying Temporal Aspects of Beam Damage

David Flannigan, Elisah VandenBussche
2020 Microscopy and Microanalysis  
Possible mitigation of damage using pulsed electron beams in the TEM has been speculated upon for decades [1] . This stems from hypotheses formulated from time-and energy-dependent processes arising from specimen excitation by the incident electrons. The myriad excitations that can occur are variably operable over a large range of timescales, from femtoseconds to microseconds and longer [2] . Further, the majority of the processes are detrimentally exacerbated (from the perspective of damage)
more » ... ective of damage) in an exponential manner with subsequent additional energy deposition [3], provided such inputs occur within the spatial region of initial excitation. Such examples include Arrhenius-type reaction rates and diffusion rates of reactive species. Additionally, local excitation of lattice phonons may produce the equivalent of significant local thermal energies that can further drive localized rate increases, despite the equilibrated global thermal-energy bath remaining quite low. Accordingly, more specific hypotheses for mitigating damage using pulsed beams focus on parameters such as the time elapsed between sequential electron arrival at the specimen and the spatiotemporal electron number density.
doi:10.1017/s1431927620020322 fatcat:z7qi73gntfemfjbp7c3wf3zdji